Difference between revisions of "De Brick or Un Bricking a WRT Series Router"

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*A TFTP Server is available and functional on the same network as the router
*A TFTP Server is available and functional on the same network as the router


=== Quick D (AKA Information) ===
===Quick D (AKA Information)===
The absolute first best thing one can do to avoid bricking a WRT / AC Series router, is to utilize the /overlay functionality and have all the important stuff stored in that manner.  Look up the /overlay thing if you're not familiar with it for more details.  In short, the boot process starts from the internal "disk drive", AKA NAND 'disk', then mounts an external USB Flash Drive or eSATA drive and continues from there based on Operating System files and settings stored on the flash drive.  That way the internal "disk drive" acts only in a similar fashion to GRUB (again, look it up).  The result of this configuration method is that the entire internal "disk drive" is disposable, can be wiped out, re-flashed, with nothing lost (except the need to install the software to recognize a USB Flash Drive and the setting to boot from it).


* OpenWRT Firmware for AC Series of Routers: https://downloads.openwrt.org/releases/19.07.3/targets/mvebu/cortexa9/
Below are some quick tips (not a step by step) that are good for bringing a 'dead' Linksys router back from the grave.
* OpenWRT De-Bricking Information: [OpenWrt Wiki] Linksys WRT AC Series
 
** run nandboot (script for booting the router from the MTD5 Partition)
*OpenWRT Firmware for AC Series of Routers: https://downloads.openwrt.org/releases/19.07.3/targets/mvebu/cortexa9/
** run altnandboot (script for booting the router from the MTD7 Partition, AKA the 'alternate')
*OpenWRT De-Bricking Information: https://openwrt.org/toh/linksys/wrt3200acm#Debricking.  Below are the key commands (''run'' being the command and what comes after it being a script stored as a variable)
** GOTCHA!: One really big "gotcha" from using the above commands relates to upgrading firmware.  When booting using the altnandboot script from above, when flashing a new image it will flash it to the current partition.  This is counter to the usual behavior where OpenWRT will flash a new image to the ''other'' parition.
**run nandboot (script for booting the router from the MTD5 Partition)
* A Recommendation: Configure the MTD6 Partition as the primary partition that boots the /overlay, and leave the secondary MTD8 partition configured to NOT boot an overlay.  This allows the MTD8 partition to function without a USB flash drive
**run altnandboot (script for booting the router from the MTD7 Partition, AKA the 'alternate')
*  
**GOTCHA!: One really big "gotcha" from using the above commands relates to upgrading firmware.  When booting using the altnandboot script from above, when flashing a new image it will flash it to the current partition.  This is counter to the usual behavior where OpenWRT will flash a new image to the ''other'' parition.
*A Recommendation: Configure the MTD6 Partition as the primary partition that boots the /overlay, and leave the secondary MTD8 partition configured to NOT boot an overlay.  This allows the MTD8 partition to function without a USB flash drive
*


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It cannot be an coincidence that the WRT32X, black in color with a code name of "Venom" and a SoC from Marvell, isn't somehow named after the 2018 Marvel movie, Venom.
It cannot be an coincidence that the WRT32X, black in color with a code name of "Venom" and a SoC from Marvell, isn't somehow named after the 2018 Marvel movie, Venom.


=== Boot Errors ===
===Boot Errors===
<syntaxhighlight lang="text">
<syntaxhighlight lang="text">
NAND read: device 0 offset 0x900000, size 0x600000
NAND read: device 0 offset 0x900000, size 0x600000
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</syntaxhighlight>
</syntaxhighlight>


=== Gotcha ===
===Gotcha===
...see above sections.
...see above sections.